This invention relates to spiral displacement machines for compressible media and, more particularly, to a new and improved displacement machine with a more effective seal arrangement.
Spiral displacement machines having a spiral displacement chamber in a stationary housing and a spiral displacement body rotatably movable in the chamber and having sealing strips engaging the support for the displacement body and the walls of the displacement chamber, which may be used as charging or compressor devices for the engines of passenger automobiles, are described, for example, in Motortechnische Zeitschrift. 1985, pp. 323-327. It has been found that, during operation of such spiral displacement machines, the wear and tear on the sealing strips varies along the length of the spiral body because of the differing axial thermal expansions of the spiral displacement bodies and the spiral housing walls forming the displacement chamber. The wear and tear is always substantially greater on the radially inner end of the spiral than on the radially outer end of the spiral during operation as a compressor since the compressible medium has a higher temperature in the radially inner outlet region of the housing than in the radially outer inlet region.